I’ve been catching up on reading recently after a fairly busy August, and have been wondering: could 2012 be the year when people in the UK wake up to the fact that our climate is changing, and possibly changing faster than anyone thought?
A lot of people you talk to about climate change are quite accepting of the fact it’s likely to happen if we don’t do something, but don’t expect noticeable effects until 2050 or so, and don’t have too much of a problem waiting another ten years for us to take action. This narrative is backed up by our own government and the international community generally. Even on a relatively positive view of the last couple of governments they seem to be pretty leisurely about the timescales of the action required, and the fact we’ll have to wait until the end of the decade at least for international agreement on carbon reduction doesn’t seem a problem.
Part of the problem is that the reports of the IPCC and climate scientists have to an extent also supported this line. Obviously there’s been considerable uncertainty both about what effects to expect and the timescale, so the mainstream have generally been reasonably conservative to avoid the charge of alarmism. Some have stuck their neck out and warned that things may be worse than the IPCC reckon, and in some areas it seems they’ve been right.
One specific data point in the news at the minute is the amount of ice in the Arctic, which has just hit a new historic low of 3500 km^3 (volume) or a bit under 4 million km^2 (area). This is about one quarter the volume or half the area that was a typical summer minimum in the 1980s. Experts have long forecast that at some point the Arctic would be largely ice-free in the summer, with a large uncertainty as to when this would occur as we don’t really understand the mechanisms behind melting that well, but with dates generally somewhere between 2040 and 2100. If the current trends continue, we are looking at it happening this decade. My sources for this are a series of articles on the Climate Progress site, see this for information on melting, and this for some more information on the consequences.
While Arctic sea ice loss may not have a major impact on us in isolation, the knock-on results are potentially quite severe. One immediate effect is that the amount of sunlight absorbed in the Arctic will increase (ice reflects a lot more sunlight back into space than water does), and the temperature rise there will accelerate. This in turn has two further consequences: affecting the jet stream and increasing methane emissions.
Again, we don’t yet know as much about these as we’d like. We do know there’s a lot of methane locked up in the Arctic permafrost, and if it starts to melt then we have a lot more greenhouse gases to deal with. One of the articles above suggests that the effect will be equivalent to 15-35% of our current annual emissions, which is bad enough. I’ve also seen reference to a paper by Malcolm Light with the cheery title of “Global Extinction within one Human Lifetime”. He warns that if we get eruptions of large amounts of methane in one place, we could get localised temperature anomalies of tens of degrees, a runaway methane problem, and resulting global temperature rises of somewhere in the region of 12-14 degrees. This takes us beyond the sudden rise that provoked the Permian extinction (the worst in Earth’s history) with mass dieoffs by mid-century in the northern hemisphere, delayed by 20-30 years in the southern.
Whether this is true or not, it shows the kind of tipping point we may well reach.
Less catastrophic, but more likely to be proven in the near-term is the effect on the jet stream. This is a band of high-speed high-altitude air which is one of the main governing factors in temperate northern hemisphere weather. What’s generally believed it will produce more extreme weather, and often “stick” for a time, which is exactly what we’ve seen happen in both the UK and USA this year – the jet stream has been way off where it normally is, and the USA has had an extremely hot summer and the UK an extremely wet one. This analysis demonstrates that since 2006 there has been a distinct pressure anomaly affecting the UK: we have had much lower pressure in the summer months each year, and a worse summer. The author isn’t sure whether Arctic melt has caused this, or vice versa, but the correlation is there so far.
And other parts of the world have had unusual weather too. Bill McKibben, in an article entitled A summer of extremes signifies the new normal lists some of the effects, and concludes with a rather chilling statistic from James Hansen: while normally only 0.1 to 0.2% of the planet was affected by an “extreme heat anomaly” at a given time, this figure has now been approaching 10%.
If we are now at the point where scientists are able to say with confidence that we are both getting more extreme weather than we used to, and that it is caused by climate change – and the American Meteorological Society for one has put out a statement to this effect – we may get a tipping point where the majority of people in the UK also believe that climate change is both real and here. (A friend who works in Uganda tells me that there there’s almost no doubt. The elders used to be able to predict the rainy season pretty reliably, but now they’ve just given up, and the people feel themselves much more at the mercy of the weather.) At least in the UK, our regular conversations about the weather seem to have changed recently, and most seem to think it’s now consistently worse than it used to be.
One interesting question is whether it will also have an effect on people’s willingness to take action. Some will undoubtedly want to do things to stop it getting worse, others may just say “it’s too late”, or – if they’ve picked up on the likelihood that things like the cost of food will probably increase due to poorer weather – batten down the hatches and be even less willing to spend money on mitigation.
But it’s at least an opportunity to reopen the debate, particularly in a time when the government’s reshuffle seems to have made it less green than before. Climate change as an issue has become “tired” for many people, but if it’s becoming real here, that could change quickly.